Upfronts 2013: Disney Junior To Be Nielsen-Rated Starting April 1

The year-old 24-hour Disney Junior channel will begin reporting Nielsen ratings on April 1, it was announced at Disney's upfront event in New York on Tuesday evening.

The preschool network also has moved three previously announced animated series in development to its 2013-14 programming slate including Henry Hugglemonster, about the five-year-old middle child of a monster family, which premieres in April. Also on deck is the preschool western Sheriff Callie's Wild West, debuting in September, with Mandy Moore as the voice of a kitty cat sheriff; and The 7D, a comedic look at the Seven Dwarfs before Snow White's arrival, which is slated for 2014.

The boy-targeted Disney XD channel will expand its Marvel Universe programming block, adding two new animated series - one based on The Hulk and another starring The Avengers.

Marvel's Avengers Assemble will have a special one-hour preview on Sunday, May 26, with the series premiere on Sunday, July 7. Hulk and the Agents S.M.A.S.H. -- which features Hulk, She-Hulk, A-Bomb, Red Hulk and Skaar living and working together to tackle threats -- debuts Sunday, Aug. 11 at 11 a.m.